Lovely portrait. I wonder if cropping a little to the right side would improve composition - it would position the child to be looking into the frame at the ball and beyond. I think it might be stronger. I like the black and white and the shallow DOF.

I like your framing, it works nicely with where the boy's head and the ball are. Nice dof and good choice of getting the background totally grass. I think I would like this shot even more if it were in colour, as kids uniforms are usually very colourful & might look nice on the green surroundings, of course just speculation on my part. Great shot!

it appears they lost. <pout>Nice use of negative space. If there is more frame to work with, try moving the negative space further out on the left hand side (putting the boy in the lower right corner). See how that looks.